According to the report by GSMA, China topped the global list of smartphone connections at 629.2 million, followed by the US (196.8 million) and Brazil (141.8 million).

Other countries in the top 10 include Indonesia, Russian Federation, Japan, Germany, the UK and France.

Several industry reports have pegged India as the fastest growing smartphone market in the world.

According to IDC, smartphone sales in India grew almost three-fold to over 44 million in 2013, buoyed by a strong uptake of affordable devices made by local firms such as Micromax and Karbonn.

GSMA expects smartphone connections to reach six billion by 2020, fuelled by growth in the developing world and supported by mobile broadband rollout.

"Smartphones will account for two out of every three mobile connections globally by 2020. The number of smartphone connections will grow three-fold over the next six years, reaching six billion by 2020, accounting for two-thirds of the nine billion mobile connections by that time," the report titled 'Smartphone forecasts and assumptions, 2007-2020' said.

Basic phones, feature phones and data terminals like tablets, dongles and routers will account for the remaining connections, it added.

"The smartphone has sparked a wave of global innovation that has brought new services to millions and efficiencies to businesses of every type," GSMA Chief Strategy Officer Hyunmi Yang said.

Smartphones will be the driving force of mobile industry growth over the next six years, with one billion new smartphone connections expected over the next 18 months alone, Yang added.

"As industry evolves, smartphones are becoming lifestyle hubs that are creating opportunities for mobile industry players in vertical markets such as financial services, healthcare, home automation and transport," Yang said.

The report forecasts that by 2020, four out of every five smartphone connections worldwide will come from the developing world.

Asia Pacific accounted for about half of global smartphone connections, even though smartphone penetration in the region is currently pegged to be below 40 percent.